Problem: $\overline{AC}$ is $7$ units long $\overline{BC}$ is $9$ units long $\overline{AB}$ is $\sqrt{130}$ units long What is $\cos(\angle ABC)$ ? $A$ $C$ $B$ $7$ $9$ $\sqrt{130}$
Answer: SOH CAH TOA os = djacent over ypotenuse adjacent $= \overline{BC} = 9$ hypotenuse $= \overline{AB} = \sqrt{130}$ $\cos(\angle ABC )=\frac{9}{\sqrt{130}}$ $=\dfrac{9\sqrt{130} }{130}$